DNA Scientists

Oswald
Avery

Discovered
DNA was the active agent in bacteria transformation

Named discovery
“transforming principle"

Oswald Avery’s
(1877-1955) greatest contribution to the field of DNA research occurred,
like so many others in our DNA story, while he was trying to solve
another problem. Avery and his team did not aim to discover that DNA
is the active agent in genetic transformation, but their “transforming
principle” opened the modern phase of DNA research.

While working
on a project to find a treatment for pneumonia, Oswald Avery, Maclyn
McCarty, Colin MacLeod and other scientists at the Rockefeller Institute
in New York were informed that one type of pneumonia could transform
into another in vivo. With this new knowledge, Avery knew that he
had to identify the conditions in which transformation could happen
and the agents that made these changes possible. To this end, Avery
and his team began the process of identifying DNA as that agent
of change in all living things.

After eliminating
large cellular pieces and proteins from the bacteria, Avery’s
team observed the transformation still taking place. However, when
all DNA was eliminated the bacteria stopped transforming. This discovery
identifying DNA as the active agent in transformation was deemed
the “transforming principle.” In 1944 it was announced
in the New England Journal of Medicine.

The “transforming principle” was in
direct opposition to the prevailing opinion of the day that proteins,
much more complex in structure than DNA, must be the agents of such
complex power and transformation. Alfred Mirsky, a renowned molecular
biologist that also worked at the Rockefeller Institute, attacked
Avery’s claims to the point of lobbying authorities in Stockholm
not to give Avery the Nobel Prize, which he never won.

In spite of these obstacles to success and recognition,
Avery’s work is now regarded as the start of the modern phase
of DNA research.

Resources

Bryson, B. (2003). A Short History of Nearly Everything.
Broadway Books: New York.